Unfruitfulness problems in Horticulture fruit Crops

1. Presentation by:
Junaid Abbas (12-Arid-374)
Zeeshan Khan (12-arid-437)

2. Unfruitfulness
 Important determinant in yield potential of
orchards.
 Causes are broadly classified as:-
1. external factors
2. Internal factors

3. External factors
 Besides change of phases in life cycle on flowering of any
fruiting plant, others factors that effect fruitfulness are:-
 Environment
 Water relations
 Nutrient Supply
 Rootstock
 Pruning
 Age & vigor of plant
 Locality
 Insect , pests and diseases
 Miscellaneous

4. Environmental Factors
 Temperature
 Rainfall
 Wind
 Frost
 Hailstorm
 Cloudy weather
 Light intensity

5. Water relations
 Moisture excess or deficit should be
avoided during critical stages .
 Undesirable fruit drop can be observed
in orchards, as a result.
 Remedies such as irrigation, tillage,
cover crops and wind-breaks can help.

6. Nutrient Supply
 Very important factor for optimum
production and avoiding unfruitfulness.
 Balanced supply of manures and
fertilizers can maximize the benefit.
 Excessive N. fertilizers can cause poor
fruit set due to carbohydrate shortage.

7. Rootstocks
 Important material in inducing desirable
benefits onto scion cultivar.
 Trees that bear fruit late can be made to
bear it early by better variety's rootstock.
 Examples include apple, pear, mango,
etc.

8. Pruning
 Important in maintaining the rhythm of
fruiting in deciduous fruit plants
 Heavy pruning is needed in raspberry,
pear & apple trees for better fruit-set
 whereas grapes require lighter pruning
for more yield by increasing cluster size.

9. Age and vigor
 Young and vigorous trees of plum and
apples show more unfruitfulness then
mature and less vigorous ones.
 Age of fruit tree is more significant factor
then its vigor while determining degree
of fruitfulness.

10. Locality
 Various factors such as soil, temperature,
humidity, light etc. constitute locality influence
on fruit-set.
 Results in changed behavior of same fruit tree
at different places, e.g. commercial mango
varieties of south Indian region don’t perform
better under north Indian conditions.

11. Insect-pests & diseases
 Mango hopper destroys ALL flowers in a mango
or the whole orchard, after infestation on its
blossoms. Other serious insect pests include
moth, leaf roller, aphids, thrips and mealy bug.
 Fire blight, Scab, and powdery/downy mildew are
serious diseases of fruits, which can be managed
through spraying and other measures to decrease
unfruitfulness in fruit trees and orchards.

12. Miscellaneous factors
 Mismanagement of orchards.
 High concentrations of highly salt.
 Continuous spray of chemicals.

14. Dio-ecious Plants
 Unisexual
 Bears only one type of Flower either
pistillate or staminate on one plant.
 Following are some examples

15. Date Palm:
 Dioecious Plant
 Proper Pollination is required
 For natural combination, male and
female trees should be in equal number.
 For artificial pollination , 1 male: 30
females is sufficient
 In General, 4 to 5 male for 100 female
trees are sufficient for commercial crop

16. Selection of Male Plant
 Following Points should be taken into
consideration
 Male plant, which produce thick and bushy
inflorescence with large number of male
strands, should be preferred
 Male strand should have abundance of pollen.
It can be judged by visual observations. Those
strand, which releases abundance of yellowish
dust on shaking are better than the others
 The male flowers that emerge early in the
season should be marked and used to avail
their pollen for pollinating early female trees.

17. Strawberry
 Widely grown dieocious fruit plant
 Most varieties bear perfect flowers
 Some of the best varieties bear pistillate
flowers only
 No proper attention was given to secure
better pollination of pistillate flowers
 Observation of Nicholas Hong worth
 He taught that such varieties should be
inter-planted with perfect flowering varieties
for a better yield

18. Papaya
1. Pure pistillate flowering plants (self fruitful)
2. Pure staminate flowering plants (un fruitful and
common)
3. Plant producing both staminate and perfect flowers
4. But with sterile pollen, more often called pseudo-
hermaphrodite plants (self fruitful)
5. But neither pollen nor pistils are fertile; more often
called sterile hermaphrodite plants(un fruitful)
6. Plant producing staminate, pistillate and perfect
flowers
7. Pistillate and perfect flowers
8. Staminate and pistillate flowers

19. Monoecious Fruit plants
 Unisexual (pistillate and staminate) flowers
are separate but borne on the same plant
at different positions like in walnut, pecan
nut, filberts, chestnut, banana, coconut and
other palms
 In most temperate fruit nuts (walnut and
pecan nut) the staminate and pistillate
flowers clusters are borne at different
positions
 Male flower(staminate) called as catkins
and female(pistillate) flower called as
spathe

20. Continued
 Pollination with the help of wind, though all
nuts are self fertile in many cases , yet
pollination is not satisfactory, because
some varieties fail to mature its pollen
when the female flowers are receptive
 Older plant grow higher number of catkins
and pollen is shed for a longer period
which makes pollination more satisfactory
and result in better crop.
 It has been recommended to grow new
walnut near to old plantation to get early
and satisfactory yield from them

21. Pseudo hermaphrodite
Flower fruit plants
 Their flowers are perfect having both
male and female sex organs but either
stamens or pistils are non functional and
they behave as staminate or pistillate
flowers such type of flowers are called
pseudo hermaphrodite flowers

22. Unusual sex distribution in
some fruit plant
 Some varieties of Japanese persimmon
present unusual sex distribution. Many of
its varieties like costa , produces only
pistillate flower year after year called as
pistillate constants
 Some varieties like eagle lake produces
only staminate flowers called staminate
constants
 Some varieties produces only pistillate
flowers in some season and both staminate
and pistillate in other season called
staminate sporadic

23. Abortion of pistils or
ovules
 If fruit setting and development depend on the union
of sex cells, any factor which hinder the process of
fertilization, would definitely result in unfruitfulness or
in sterility
 Any interference during flower stamen or pistil
development is largely responsible for poor fruit set
in many fruit plants e.g mango
 In number of species and varieties the pistils and
ovules appear to be normal but partial or complete
degeneration in the embryo sac prior to its maturity
may affect the fertilization process and ultimately in
the fruitfulness of that species. However it may be
noted the abortion of a plant of the ovules does not
lead to necessarily to unfruitfulness

24. Pollen Importance
 Beach(1898) was the first scientist to
realize the importance of pollen viability
in deciduous fruits
 He concluded that on the basis of pollen
viability, the varieties of American grape
can be grouped into three classes self
fertile, self sterile and partly self sterile

25. Thank you
for your time
